Heat exchangers of the liquid-air type used in automotive vehicle cooling systems, air conditioning systems and the like, involve considerable labor to produce. Where automatic machinery is used to produce the exchanger, especially where weldment construction is employed at the joints uniting the parts, there is frequently a large percentage of rejects because of pinholes, fissures and other leakage openings in one or more of the weldment joints. Even one such leakage opening results in rejecting the exchanger. Such an opening is ordinarily difficult to locate and laborious and expensive to correct.
The method of this invention permits the step-by-step mass production of heat exchangers and avoids substantially entirely the leakage problem by providing a sealant coating of solder over the air side of the welds which are themselves on the liquid side. In addition, any leakage is from the liquid interior of the heat exchanger to the outer air side so that its detection and correction are easily accomplished.
The invention will be described in one embodiment thereof as illustrated in the accompanying drawings.